View source for 1tty


==Solution structure of sigma A region 4 from Thermotoga maritima==
<StructureSection load='1tty' size='340' side='right'caption='[[1tty]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1tty]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TTY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TTY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tty FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tty OCA], [https://pdbe.org/1tty PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tty RCSB], [https://www.ebi.ac.uk/pdbsum/1tty PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tty ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SIGA_THEMA SIGA_THEMA] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the primary sigma factor during exponential growth.[HAMAP-Rule:MF_00963]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tt/1tty_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tty ConSurf].
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== Publication Abstract from PubMed ==
Bacteriophage T4 AsiA is a versatile transcription factor capable of inhibiting host gene expression as an 'anti-sigma' factor while simultaneously promoting gene-specific expression of T4 middle genes in conjunction with T4 MotA. To accomplish this task, AsiA engages conserved region 4 of Eschericia coli sigma70, blocking recognition of most host promoters by sequestering the DNA-binding surface at the AsiA/sigma70 interface. The three-dimensional structure of an AsiA/region 4 complex reveals that the C-terminal alpha helix of region 4 is unstructured, while four other helices adopt a completely different conformation relative to the canonical structure of unbound region 4. That AsiA induces, rather than merely stabilizes, this rearrangement can be realized by comparison to the homologous structures of region 4 solved in a variety of contexts, including the structure of Thermotoga maritima sigmaA region 4 described herein. AsiA simultaneously occupies the surface of region 4 that ordinarily contacts core RNA polymerase (RNAP), suggesting that an AsiA-bound sigma70 may also undergo conformational changes in the context of the RNAP holoenzyme.

T4 AsiA blocks DNA recognition by remodeling sigma70 region 4.,Lambert LJ, Wei Y, Schirf V, Demeler B, Werner MH EMBO J. 2004 Aug 4;23(15):2952-62. Epub 2004 Jul 15. PMID:15257291<ref>PMID:15257291</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Sigma factor 3D structures|Sigma factor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermotoga maritima]]
[[Category: Demeler B]]
[[Category: Lambert LJ]]
[[Category: Schirf V]]
[[Category: Wei Y]]
[[Category: Werner MH]]